Burglar-alarm.



No. 759,615. PATBNTED MAX 1o, 1904. A. J. KBRCHER, BURGLAR ALARM.`

APPLIUATION I'InEI) OQ'LS, 1903.

a sHBn'rs-SHBHT 1.

no nonni..

PATBNTED MAY 10, 1904.

A. J. KERCHBR. BURGLAR ALARM.

APPLIUATIOH FILED 00T. 9, 190s.

3 SHEETS-SHEET 2.

no l/onm..

vs/Jaca Ffa:

@SHEETS-SHEET 3.

PATENTED MAY 10, 1904. A. J. KBRCHER. BURGLAR ALARM.

APPLIOATION FILED olxa, 1903.

u, fun.

N0 MODEL.

r ,o W a.

UNITED STATES Patented May 10, 1904.

PATENT OEEICE.

ARTHUR J. KEROHER. OF MINNEAPOLIS, MINNESOTA, ASSIG-NOR OF ONE- HALF TO A. S. THOMAS ANI) G. N. KEROHER, OF MINNEAPOLIS, MIN- NESOTA.

BuRGLAn-ALARM.

SPECIFICATION forming part of Letters Patent No. 759,615, dated May 10, 1904.

Application filed October 9, 1903.

To (1J/Z whom t may concern:

Beitknown thatI, ARTHUR J. Kanonen, ot' Minneapolis, county of' Hennepin, State of Minnesota, have invented certain new and useful Improvements in Burglar-Alarms, of which the following is a specification.

My invention relates to burglar-alarm systems designed particularly for use in connection with banks and safety-deposit vaults, though equally well adapted for dwelling'- houses and other structures.

The object of thisinvention is to provide means in connection with a bank or safetydeposit vault or other structure to be pro: tected for sounding an alarm within or near thc structure or at a distance therefrom should any one attempt to force an entrance into the vault or structure or measure the static charge or in any Way talnper with the electric conductors.

A further object is to provide a burglaralarm system employing' open-circuit conductors, thereby greatly reducing battery consumption.

Other objects of the invention will appear from the following detailed description.

The invention consists generally in providing statically-charged conductors of opposite polarity connected with the structure to be protected, a local alarm-circuit, and an electrostatic apparatus charged from said conductors and arranged to close said alarm-circuit upon any variation of the normal difference of potential of said conductors.

Further, the invention consists in various constructions and combinations, all as hereinafter described, and particularly pointed out in the claims.

1n the accompanying drawings, forming' part of this speciiication, Figure 1 is a View showing the application of the apparatus to the vault. Fig'. 2 is a front elevation of the electrostatic apparatus that is connected with the alarm-circuit and with the statically-charged conductors leading from the structure to be protected. Fig. 3 is a ,vertical sectional view of the electrostatic apparatus, showing the manner of connecting said apparatus to Serial No. 176,359. (No model.)

the source of electrical energy and to the alarm-circuit- Fig. l is a perspective View showing the manner of supporting the contact-points of the movable terminals of the electrostatic apparatus.

ln the drawings, 2 represents a vault or other structure to be protected, and 3 an alarm station or box located outside and near the vault or atadistance therefrommas a police-station, the bankers residence, or any other suitable place.

4 represents the protective lining provided on the interior walls of the vault, and A is a battery forming the source of electrical en ergy. The positive and negative terminals of the battery are connected, respectively, to conductors B and C, that are carried out through the walls of the vault or other structure, the conductor B preferably being connected to a resistance-coil 5 and inductionplates 6, having a series of points 7. These points are suiiiciently near each other to cause one plate to become charged by induction from the other and will prevent the formation of a current should any one tamper with the wires or attempt to measure the charge with an ordinary voltmeter. The resistancc-coil will cut down the potential, and provision may bemade for increasing or decreasing the resistance at will, and thereby render it practically impossible 'for any one to connect the wires and measure the charge with a view of making the system inoperative, except with the use of the most delicate instrument, and even then the alarm is almost certain to be sounded. The apparatus is entirely operative without this resistance-coil and the induction-plates; but I may employ them as an additional safeguard. The conductor B, which we will assume leads from the positive pole of the battery, is eX- tended on beyond the induction-plates 6 and is connected to a binding-post 8, mounted on a block 9 or' insulating material. Upon this block 9 I provide fixed terminals D, each comprising a series of quadrant-shaped plates l0, arranged in groups upon each side of the center of said block and mounted upon screws 1l, provided with collars 12, that separate said plates 10 from each other. The conductor B is continued from the binding-post 8 to these plates 10, which Vform the fixed terminals of the electrostatic apparatus. Between the fixed terminalsIprovide a movable terminal or vane E, comprising a hub 13, mounted on a shaft 14, that llas pin-point bearings on the block 9 and a bracket 15 and insulated from the plates 10, as shown.A Upon each side of the hub 13 I mount a series of plates 16, adapted to pass between the plates 1() of the fixed terminals without contacting therewith when the said vane is oscillated. One fixed terminal is arranged on one side of said movable terminal at one end and the other fixed terminal on the opposite side at the other end. The conductor C, leading from the negative terminal of the battery, is connected to a binding-post 17 and from thence leads to the bearing of the oscillating vane which forms the movable terminal for the negative pole of the battery and is statically charged therefrom. The plates at the upper end of the vane E have a metallic connection 18, provided with an upwardlyturned end 19, forming one of the movable contact-points, several-of which I prefer to provide in this apparatus.

In carrying out my invention I make use of the principle of electrostatics, and arrange a staticallycharged device or relay at the alarm box or station, connected by corre-v spondingly-charged conductors with a source of electrical energy in the structure to be protected. rThere are no closed circuits through the apparatus, and consequently no consumption of battery energy. The oscillating vane or movable terminal normally tends to swing by gravity away from the fixed terminals and close the local alarm-circuit; but when the conductors and their terminals are statically charged the attractive forces of the fixed terminals will cause the movable terminal to swing toward and between the quadrant-shaped plates and open the alarm-circuit, andthe movable terminal will be held in this position as long as there is no variation in the normal difference of potential of said conductors, the proper relative positions of the contact-points and the terminals having been determined by experiment. If a variation of potential other than normal should occur through tampering with or severing the conductors or for any other reason or should the battery run down or be destroyed, the movable terminal will swing away from the fixed terminals and close the alarm-circuit, as will be hereinafter described in detail. This use of statically-charged fixed and movable terminals is old in electrostatic voltmeters, particularly those of the multicellular type, and hence I make no claim, broadly, to the same herein, my invention residing in the application of a device embodying these electrostatic characteristics to a burglar-alarm system.

To increase the sensitiveness of the apparatus, l prefer to duplicate the fixed and movable terminals above described, on the other side of the supporting-block 9, using the same reference-numerals, but priming them, for convenience of description and to avoid confusion. A positively-charged conductor B leads from the induction-plates 6 to the binding-post 8 and from thence to the plates 10 ofthe fixed terminals D, and a negativelycharged conductor C leads from a negative pole of the battery to a binding-post 17 and from thence to the hub of the movable terminal E. T he plates at the upper end of this terminal have a metallic connection 18 and upwardly-turned parts forming contact-points 19 and 19 upon each side of the point 19. The vanes or movable terminals are mounted so that when they are not charged the points will contact by gravity, and, as above describedI with reference to terminal E, contact will also take place when any difference of potential other than normal for which the instrument is adjusted exists in the terminals through any one attempting to measure the charge, sever one or all of the conductors, or in any way tamper with the apparatus. Conductors 2O and 20 lead from the movable terminals E and E to binding-posts 21 and 21 and from thence through the battery C to the drop F. A conductor 22 leads from the drop F to the battery C, and similar conductors 23 and 23 connect the drop and battery with an alarm-bell H. Contact of the point 19 with either of the other points 19 and 19l will actuate the drop and close the alarm-circuit.

In a burglar-alarm system of this kind it is desirable to provide some means whereby the banker or other person in charge of the vault or other' structure Can vary from time to time the potential of the charge in the conductors for the purpose of rendering it more difficult to measure the said charge or in any way tamper with the conductors without causing an alarm to be sounded. With this end in View I provide a switch 24, having a series of contact-points a, c, CZ, e, f, g, and L, connected, respectively, with the negative poles of the battery by the conductors C and C and conductors c, CZ, f', g, and 71,. Binding-posts 25 and 25 are provided on said switch, to which the conductors C and C are connected, and xed contact-surfaces 26 and 26 are connected, respectively, with the posts 25 and 25 by conductors 27 and 27. An insulatingblock 28 is centrally mounted on said switch and provided with movable contact-plates 29 and 29, that are adapted to bear, respectively, on the fixed surfaces 26 and 26 and engage the contact-points above referred to as the block 28 is revolved. As will appear from the foregoing description, th'e conductors C and C are connected, respectively, with the movable terminals or vanes of the electrostatic apparatus, and as these terminals carry the contact- IOO ITO

ISO

points it is essential to change the potential of the static charge in each terminal or main tain the same ratio between them, so that when the potential is changed there will be no danger of closing the alarm-circuit. Normally the terminal E will be charged through the conductor C, receiving the entire static charge of the negative pole of the battery. The other movable termin al will receive a charge of similar polarity, but of less potential, throug'h the conductors /1/, 27', and C. Suppose now the person in charge of the vault desires to vary the potential in the negative terminals, still maintaining the same ratio between them, and swings the block 28 and moves the contactplates 29 and 29 from the points a and li, to the points I) and g, for instance. The movable terminals will then be negatively charged through the conductors b', g', C, and G; but the charge will be of less potential than before the switch was operated, as a portion of the battery has been cut out. The further movement of the switch will still further reduce the static charges in the movable terminals; but the ratio between them will remain constant throughout the entire range of movement of the switch. This apparatus will allow the banker to change the potential of the static chargesV in the movable terminals whenever he desires and render it practically impossible for any one to measure them without closing the local alarm-circuit, and even the men who installed the system after leaving the work will be ignorant of the potential of the charge in themovable terminals. To still further safeguard the apparatus and render it still more diiiicult to apply an instrument to the conductors to measure a static charge or cut out the alarm, I prefer to provide a pole-changing device consisting of a series of contact-points 30, 31, 32, 33, 84, and 35. The points 30, 3l, 33, and 34 are connected, respectively, with the conductors B, C', B, and C, and conductors B" and C" connect conductors B and B', respectively, with the points 32 and 35. 36 is a longitudinally-movable bar pivoted at one end to an arm 37 onashaft 38, provided with an operating-handle 39. Con tact-springs 30', 32', 34C', and 35 are pivoted at one end and connected at a point intermediate to their ends to the bar 36 and at their free ends adapted to bear on `the contactpoints above referred to. A weight 40 is mounted on the shaft 38 and when swung toward the left, as shown in the ligure, tends to depress the bar 36 and move the contactsprings into engagement with the points 3l, 32, 34C, and 35. In this position the fixed terminals of the multicellular apparatus will be positively charged and the movable terminals negatively charged, all as heretofore described in detail. Suppose, however, the weight 40 be moved to the position indicated by dotted lines in the figure, the bar 36 will be elevated, moving the contact-springs into engagement with the points 30, 3l, 33, and 34.

The polarity of the conductors and terminals will then be reversed, and the. change will occur so quickly that the contact-points carried by the movable terminals will not be aifected to close the alarm-circuit.

The manner of using my invention is as fellows: The electrostatic device or relay is located at the alarm-station, which may be inV the bankers residence, a police-oilice, or any other suitable place and is connected with a local alarm-circuit that is normally open and with conductors that are always open and lead to a source of electrical energy, preferably a primary or secon dary battcry,arranged within the vault or other structure to be protected. The resistance-coil, the induction-plates, the switch and pole-changer are also located within the protected structure, where they are accessible to the banker or person in charge of the vault for varying the potential of the movable terminals or changing the static charges in the `fixed and movable terminals from positive to negative, or vice versa. From the foregoing detailed description it will be evident that though the movable terminals are balanced, so that when normally charged they will be out of contact with each other and held suspended between their iixed terminals by the attractive forces of the static charges, their tendency, however, will be to contact with each other by gravity and close the local alarm-circuit, and this will happen if any4 variation from the normal occurs in the potential difference of the said charges, as when the conductors, or any one of them, are cut or a short-circuit established or the battery run down.

I do not' wish to be confined to the particular construction of electrostatic apparatus shown herein or to the form of switch and pole-changer employed or to the use of a resistance-coil and induction-plates, as the same may be varied or omitted without altering the character of my invention, which consists, essentially, in the application of an elctrostatic apparatus employingopen circuits to an alarm system.

I claim as my inventionl. In a burglar-alarm system, a source of electrical energy, statically-charged conduc tors of opposite polarity leading therefrom, a local alarm-circuit, and a device having lixed and movable terminals o ppositely charged through said conductors and arranged to close said alarm-circuit when a variation occurs in the normal potential difference of said eonductors, said movable terminal being arranged between said iixed terminals and normally tending to contact by gravity with one of them.

2. In a burglar-alarm system, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, a pole-changing device connected with said conductors, a local alarm-circuit, a contact-point in circuit therewith, adevice having fixed and IOO movable terminals of' opposite polarity statically charged from said conductors and arrang'ed to close said alarm-circuit when a variation occurs in the normal potential difference of said conductors.

3. In a burglar-alarm system, a source of electrical energ'y, statically-charged conductors of opposite polarity leading' therefrom, a local alarm-circuit, a contact-point in circuit therewith, an apparatus connected with said conductors and adapted to be electrostatically charged therefrom, said apparatus comprising fixed and movable terminals, said fixed terminals being arranged at the ends and upon each side of said movable terminals, and the latter being' normally held out of contact with said point by the attractive forces of said statically charged fixed terminals but arrang'ed to contact with said point and close said alarm-circuit upon a variation from the normal potential dierence of said conductors.

t. In a burg'lar-alarm system, a source of electrical energy, statically-charged conductors of opposite polarity leading' therefrom, a local alarm-circuit, a contact-point in circuit therewith, an apparatus connected with said conductors and adapted to be statically charged therefrom, said apparatus having fixed and movable terminals comprising quadrant-shaped plates and an oscillating' vane between them, and said terminal being normally held out of contact with said point by the attractive forces of said statically-charged fixed terminals but arranged to contact by gravity with said point and close said alarm-circuit upon the severing of any of said conductors.

5. In aburglar-alarm, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, there being' a dierence of potential in some of the conductors of the same polarity, a local alarmcircuit, a device having a plurality of fixed and movable terminals adapted to be oppositely charged through said conductors and arranged to close said alarm-circuit when a variation occurs in the normal potential difference of said conductors.

6. In an electric alarm, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, a local alarm-circuit, a device having a plurality of fixed and movable terminals oppositely charged respectively through said conductors, said movable terminals being operable independently of each other and connected with conductors of dierent potential but of the same polarity and arranged to close said alarmcircuit when a variation occurs in the normal potential difference of said conductors.

7. In an electric alarm, a source of electrical energy, statically-charged conductors of opposite polarity leading' therefrom, a local alarm-circuit, a multicellular device having a plurali ty of oppositely-charged fixed and movable terminals arranged in pairs and connected with said conductors, said movable terminals being operable independently of each other, contact-points carried by said movable terminals and in said alarm-circuit and arranged to contact with each other and close said circuit upon the occurrence of a variation in the normal potential difference of said fixed and movable terminals.

8. In an electric alarm, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, a local alarm-circuit, a multicellular device having a plurality of oppositely-charged fixed and movable terminals arranged in pairs and connected with said conductors, said movable terminals being operable independently of each other, contact-points carried by said movable terminals and in said alarm-circuit and arranged to contact with each other and close said circuit upon the occurrence of a variation in the normal potential difference of said fixed and movable terminals, and means arranged in said conductors for varying the potential of the static charg'e in said movable terminals while maintaining' a constant ratio between them.

9. In a burglar-alarm system, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, a local alarm-circuit, a device having fixed and movable terminals oppositely charged through said conductors and arranged to close said local circuit when a variation occurs in the no1'- mal potential difference of said conductors, said movable terminal being arranged between said fixed terminals and normally tending to contact with one of them.

l0. In a burg'lar-alarm system, a source of electrical energy, statically-charged conductors of opposite polarity leading therefrom, a local circuit, a contact-point in circuit therewith, an apparatus connected with said conductors and adapted to be statically charged therefrom, said apparatus having fixed and movable terminals comprising charged surfaces, and an oscillating' vane between them, and said movable terminal being' normally held out of contact with said point by the attractive forces of said statically-charged fixed terminals but arranged to contact with Said point and close said alarm-circuit upon the severing of any of said conductors.

In witness whereof I have hereunto set my hand this 6th day of September, 1903.

ARTHUR J. KERCHER.

In presence of- RICHARD PAUL, M. HAGERTY.

IOO

IIO 

